This proposal seeks a five-year continuation of Monitoring the Future, an ongoing epidemological research and reporting project. Begun in 1975, the project functions as a basic research study, as well as one of the country's major sources of reliable information on trends in drug use. It is based on two interconnected series of surveys using nationally representative samples: (a) an annual survey of seniors in high schools (about 17,000 per year in 135 high schools), and (b) annual follow-up surveys of panels (of about 1,200 people from each graduation class), followed by mail for up to sixteen years past high school. Thus, the populations under study consist of American high school students, college students, and most men and women through age 34. The study's cohort-sequential design permits the differentiation of three types of change over time-secular, maturational and cohort- each of which tends to have quite different types of determinants, and all of which have already been found to occur for at least some drugs. In addition to monitoring many types of drug use, along with a host of factors which may help to explain secular trends in them, the project has the additional objectives of documenting the natural history of use through this part of the life cycle, of determining what transitions in social roles and social environments contribute to that history, and of determining what features of those roles and environments are of particular importance. It also seeks to examine the importance of many other hypothesized psychological, behavioral, and social determinants of drug use (including attitudes and beliefs about drugs, and various lifestyle orientations) as well as range of potential consequences of drug use (including physical health, psychological well-being, status attainment, and role performance). The fact that these multiple aims and multiple populations are encompassed in a single, integrated study is both synergistic and cost effective. The measurement content contained in the study's five different questionnaire forms is exceptionally broad. It includes: (a) the use of some 30 classes and sub-classes of licit and illicit drugs; (b) perceived availability, perceived peer norms, and attitudes and beliefs, about the use of many of these drugs; (c) a number of characteristics of the person in other domains (behaviors, attitudes, beliefs, health symptoms, achievements, lifestyle variables); and (d) many aspects of major social environments (school, job, college, home) and of role statuses and experiences (marriage, parenthood, divorce, employment, education) both during and after high school. A wide range of publications is planned.